1. Field of the Invention
The present invention relates to a semiconductor device constituted of a stack of semiconductor modules, each module having a structure in which at least one semiconductor chip formed with a semiconductor power element is resin-molded together with a heat spreader (heat radiating plate) for dissipating heat generated by the semiconductor chip.
2. Description of Related Art
Such a semiconductor device is described, for example, in Japanese Patent Application Laid-open No. 2006-165534. In the semiconductor device described in this patent document, a semiconductor chip formed with semiconductor power element, and a heat spreader for dissipating heat generated by the semiconductor chip are resin-molded as an integrated resin mold section, the resin mold section being formed with a water channel through which cooling water flows. More specifically, the semiconductor chip and the heat spreader are resin-molded in the form of a plate-like unit, and a plurality of the plate-like units are stacked such that the water channels of the respective units are joined to one another.
In the above semiconductor device, each of the units is provided with a bus bar to which its power terminal (positive terminal) is connected, and the bus bars of the respective units are electrically connected with one another by welding or soldering.
The above conventional semiconductor device has a problem in that, since a welding or soldering process has to be performed to connect the power terminals of the respective units with one another through bus connection, the manufacturing cost is high because of its complicated manufacturing process and high components count.